Palm. Simple and with just a giant screen (sort of!). It deserved to evolve into today's smartphones, and I still find it astonishing it didn't.

One can easily argue that it did ...just not from the same company.

Evolution doesn't happen only via reproduction... http://en.wikipedia.org/wiki/Horizontal_gene_transfer - actually, that might be the primary way among the dominant form of life on this planet (dominant at least by biomass; but also crucial overall; and, well, there are more bacterial cells in our bodies than "human" ones). Plus, the genome of your mitochondria (some of it even subsequently transferred to nuclear DNA) came from ~bacterial kingdom...